Solvent composition



Patented Jan. 29, 1935 1,989,478 SOLVENT COMPOSITION John J. Grebe, Sylvia M. St'oesser, and Lindley E. Midland, Mich., assignors to The Dow Chemical Company,'Midland, Mich., a corporationof Michigan No Drawing. Application March a Serial No.59a4oa 6 Claims. (01. 87-5) The invention regards a-composition of matter suitable for use as a solvent; particularly a solvent which may be employed in the dry cleaning and spotting field. 7

It is well known to 'admix carbon tetrachloride with naphtha, or petroleum distillate, to increase the flash point of the naphtha to about 105' F. which is abovethe temperature normally found in cleaning establishments or homes. However, it' is practically impossible to obtain a mixture consisting of naphtha and carbon tetrachloride,

wherein the quantity of naphtha present exceeds 10 per cent by volume, which will be non-explosive under all conditions. In order to pass the National Board of Fire Underwriters test as a non-hazardous fluid, such fluid must be non-explosive throughout its entire evaporating range. It will readily be seen that a composition of matter having qualities equal or superior to ordinary cleaning solvents, meanwhile meeting the Underwriters requirements for non-hazardous fluids, would be very desirable.

We have found that a composition of matter having superior cleaning properties may be prepared by mixing naphtha or a petroleum distillate, carbon tetrachloride and tetrachlorethylene, and further that this composition will meet the requirements of the Underwriters test for nonhazardous fluids.

Accordingly it is an object of this invention to set forth the proportions in which the aforestated ingredients can be combinedto obtain a nonexplosive solvent which may be utilized for dry cleaning and spotting purposes.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the features hereinafter fully describedand particularly pointed out in the claims, thefollowing description setting forth in detail severalapproved combinations. of ingredients embodying our inboiling points of the petroleum distillate under consideration.

As an example of a low-boiling naphtha,; the

distillation range of a 100 c. 0. sample of one such fluid is here given:-

Boiling Range First drop 72. 3 0. c. c. 76. 3 C.

40 75. 3 Dry 84. 3

Sp. r. at 15 c.=.779.

. As an example of a high-boiling naphtha, the distillation range of a c. 0. sample of one such fluid is here given:-

Sp. gr. at 20 C.= .746.

All percentages hereinafter ages by volume.

We have found that either of these naphthas can be incorporated into a. mixture of carbon tetrachloride and tetrachlorethylene in amounts up to 20 per cent thereof without causing the mixture to become explosive. The relative percentages of carbon tetrachloride and tetrachlorethylene in the mixture will depend upon the boiling range of the naphtha used.- When a naphtha having a low boiling range is used, we

given are percenthave found that it is necessary to use a preponderating proportion of carbon tetrachloride. Conversely, when'a high boiling range naphtha is used a preponderating proportion of tetrachlorethylene is required. Thus the proportion of carbon tetrachloride may be between about 20 and about 88 per cent, and the proportion of tetrachlorethylene may be between about 2 and about 70 percent of the total composition.

As a specific example, naphtha having a distillation range of 72.3-84.3 C. was mixed in the amount of 20 per cent with 2 per cent tetrachlorethylene and 78 per cent carbon tetrachloride. As another example, 20 per cent of this same naphtha was admixed with 5 per cent tetrachlorethylene and 75 per cent carbon tetrachloride. Both of these mixtures meet the Underwriters specifications for non-hazardous fluids.

A commercial naphtha having a wider boiling range, between 70-108 0., was used to prepare .a. non-explosive mixture consisting of 15 per cent of such naphtha, per cent tetrachlorethylene, and 75 per cent carbon tetrachloride.

We have found that by admixing 20 per cent of a high-boiling naphtha such as that hereinbefore mentioned having a boiling range of 86-l34 C. with 60 per cent tetrachlorethylene and 20 per cent carbon tetrachloride that a nonhazardous fluid may also be prepared. As a second example, a mixture consisting of 20 per cent of naphtha, 30 per cent of carbon tetrachloride,

and 50 per cent of tetrachlorethylene was pre pared which gave like results.

The following table shows in part the relative detergent properties of carbon tetrachloride, tetrachlorethylene, and a standard naphtha known to the trade as Stoddard Solvent:-

Carbon tetrachloride Tetrachlorethylene Stoddard Btam solvent Used machine 011 God Millr Butter Mayonnaise dressing..- Gravy w r r s s ssas a r in se s s w s r r e s -a? R-Removed by washing P. R.Partly removed by washing X-Not removed at all It will readily be seen that tetrachlorethylene and carbon tetrachloride remove a number of .stains which are not aifected by the naphtha.

was reached.

mind Time Carbon tetrachloride 2 minutes, 45 seconds 5 percent tetrachlorethylene..

75 per cent carbon tetrachloride 2 minutes, 50 seconds 20 per cent naphtha (70-85 0.)-.- 50 per cent tetrachlorethylene 30 per cent carbon tetrachloride. 20 per cent naphtha (701-108" C. Tetrachiorethylene 5 minutes, 30 seconds Stoddard solvent 30 minutes, 00 seconds minutes, 00 seconds The ingredients in our composition may be varied from the specific proportions hereinbefore stated in the following marlner:the percentage of naphtha present may be between 10 and 20 per cent. When a low-boiling naphtha is used the percentage of tetrachlorethylene may be varied between 2 and 10 per cent, the percentage of carbon tetrachloride being varied in accordance so that the total percentage of carbon tetrachloride and tetrachlorethylene will be between 80 and 90 per cent, 1. e. the percentage of carbon tetrachloride will be between about '70 and 88 per cent. Using a high-boiling naphtha the amount of carbon tetrachloride may be varied between 20 and 30 per cent, the percentage of tetrachlorethylene being varied so as to make the total percentage of tetraclorethylene and carbon .tetrachloride between 80 and -90 per cent, i. e. the percentage of tetrachlorethylene will be between about 50 and 75 per cent. If 20 per cent of a naphtha having a boiling range between 72.3 and 13d C. be used in preparing the composition, the proportions of carbon tetrachloride and tetrachlorethylene used should be substantially equal. Thus, equal proportions of two naphthas-having boiling ranges, respectively, between 72.3-84.3 C. and 86-134 C. may be used to prepare a mixture wherein such naphtha is present to the extent of 20 per cent, tetrachlorethylene 40 per cent and carbon tetrachloride 40 per cent, the mixture being non-hazardous.

Among the advantages of such a composition of. matter, when used as a dry cleaning solvent, are its complete freedom from fire and explosion hazard, and its superior detergent properties. The tetrachlorethylene is not corrosive under any conditions, and, further, minimizes the tendency of carbon tetrachloride to hydrolyze. Tetrachlorethylene is only slightly more toxic than carbon tetrachloride when equal parts per million of the two substances are present in air. However, because of its lower vapor pressure the concentration of tetrachlorethylene in air during ordinary usage as a cleaning solvent is less toxic than carbon tetrachloride. We have found that the partial vapor pressure of carbon tetrachloride at room temperature is 12 per cent of the total atmospheric pressure whereas tetrachlorethylene at comparable temperature has a partial vapor pressure of only 2.0 per cent, in other words, only about 0.16 as much tetrachlorethylene as carbon tetrachloride can be present in equilibrium with air at normal room temperature. The vapor pressure of a mixture of carbon tetrachloride and tetrachlorethylene is lower than the vapor pressure of carbon tetrachloride alone, therefore such mixture is less toxic than carbon tetrachloride used alone.

Among the principal advantages enjoyed by our non-explosive, non-inflammable composition of matter are; that it may be safely stored in any quantity, that it may be kept and used in!- the home, industrial, or commercial establishments under all conditions without danger, and that it possesses detergent properties not hithertofound in dry cleaning solvents.

Other modes of applying the principle of our invention may be employed instead of those explained, change being made as regards the materials employed, provided the ingredients stated by any of the following claims or the equivalent of such stated ingredients be employed.

We therefore particularly point out and distinctly claim as our invention:

1. A composiiton of matter which is non-inflammable and non-explosive over its entire evaporating range consisting of from 10 to 20 per cent of a petroleum distillate having a boiling point range between about 70 and about 134 C., from 20 to 88 per cent of carbon tetrachloride and from 2 to 70 per cent of tetrachlorethylene.

2. A composition of matter which is non-inflammable and non-explosive over its entire evaporating range consisting of from 10 to 20 per cent of a petroleum distillate having a boiling range between 70 and 110 0., from 2 to 10 per cent of tetrachlorethylene and from '10 to 88 per cent of carbon tetrachloride.

3. A composition of matter which is non-inflammable and non-explosive over its entire evaporating range consisting of from 10 to 20 per cent of a petroleum distillate having a boiling range between 70 and 85 C., from 2 to 10 per cent of tetraclorethylene and from '70 to 88 per cent of carbon tetrachloride.

4. A composition of matter which is non-mflammable and non-explosive over its entire evaporating range consisting of approximately 20 percent of a petroleum distillate having a boiling range between 70 and 85 0., approximately 5 per cent of tetrachlorethylene, and approximately 75 per cent of carbon tetrachloride.

5. A composition of matter which is non-inflammable and non-explosive over its entire evaporating range consisting of from to per cent of a petroleum distillate having a boiling range between 86 and 134 C., from 20 to per cent of carbon tetrachloride and from to per cent of tetrachlorethylene.

6. A composition of matter which is noninflammable and non-explosive over its entire evaporatingrange consisting of approximately 20 per cent of a petroleum distillate having a boiling range between 86 and 134 0., approximately 30 per cent carbon tetrachloride, and approximately 50 per cent tetrachlorethylene.

JOHN J. GREBE. SYLVIA M. STOESSER. 

